[Continued from Part I, which you can find here.]
Once a beer has been properly transported home, stored and chilled, glassware becomes the issue. You've probably heard the term "beer clean," and cleanliness is very important. A beer clean glass is what allows a great beer to not only look great, but also smell, feel and therefore taste like a great beer. If you ever see bubbles sticking to the bottom or sides of a glass, that means it is not completely clean. The cause of this is often invisible oil or sugar, and that is why hand washing is the most infallible method; when you feel that "squeaky" clean sensation, you know the glass is clean. Lessons in dishwashing aren't very fun, but drinking from a beer clean glass is, so it balances out. I've gotten lazy about this before and paid for it when my new, exciting beer didn't end up being as appealing as I expected.
A dirty glass leads to lower carbonation because unclean parts of the glass create many agitation points, which release CO2 very quickly after you pour the beer. Less carbonation means less aroma, which is a tragedy for most styles. When oil dissolves in the beer, the head will diminish much more quickly, too. I prefer to use a dry glass, though some water drops on the sides will not significantly affect the beer. If tasting several beers, a new glass isn't usually necessary. Rinsing with water is fine, but rinse strong-smelling, intense beer out very thoroughly and make sure to dissolve sticky lacing, too.
The next step is pouring, which mostly revolves around creating head. The issue of that foam on top of beer has little to do with personal preference, though to me, not desiring a fair amount of head on your beer is akin to not wanting your food nicely browned or charred on the grill; it is the cherry on top that actually adds complexity to the whole sundae. Head adds a unique and contrasting texture to the effervescent liquid below, thus leading to a more satisfying, layered tactile experience. If served properly, it might even tell you the style of beer below.
A towering, pure-white, dense head could easily be a hefeweizen, whereas very hoppy beer usually has a soapy, finely-bubbled and slightly rocky head. If you encounter a gigantic head with lots of peaks and valleys that stick to the sides of the glass in clumps, it's most likely atop a bottle-conditioned wild ale. The presence of a proper head tells you if the beer will be a good representation of the style. You'll rarely taste a good IPA with a tiny head made up of a few large bubbles. If brewed and served well, the hop oils should prevent such diminutive foam. However, a very sour, fruited beer will most likely have an unimpressive head because of its high acidity and little to no hop character, and that is perfectly acceptable (because it's almost physically unavoidable).
To create the appropriate head and overall appearance, which will then complement the other attributes of the beer, you could educate yourself about the beer's style, carbonation method, and age. This will help you greatly during the crucial moment of pouring. Since most beer is force-carbonated with about the same volumes of CO2 per liter, it's often a simple process. What happens when the beer hits the glass is consistent, predictable, and requires little thought, especially if you're using a familiar glass.
If the carbonation method used is bottle-conditioning (adding sugars to the bottle with live yeast to ferment them and spit out CO2), or there appears to have been yeast activity (i.e. significant sediment on the bottom after aging) you can do a few things to prevent an overly heady pour or gushing upon opening. Place the beer in the fridge for a few days to "calm down" the beer, then open slowly and carefully. If you hear a loud and long pfft or hiss while opening, it is a very carbonated beer indeed, so pour very slowly down the side of the glass at first to see how strong the carb is, and adjust pouring speed according to how much head you'd like. The head of wild yeast fermented beer may continue to climb after the pour has ended, so be extra gentle. When a beer is bottle-conditioned with Brettanomyces, it may even gush or spray after opening, so make sure glasses are ready and the sink is near. This caution isn't usually necessary, though, and when others are pouring beer for me, I often request a hard pour because otherwise, I'll get a headless glass of beer. It seems that many think a big head means a bad pour. Perhaps it's in part because you get more beer if the liquid goes all the way to the top of the glass, but I'm willing to sacrifice an ounce for the added pleasure and information I get from a nice head.
A beer that's been in the bottle for a year or more will likely have a little sediment at the bottom. Beyond the visual aesthetics of clear versus hazy beer, the taste and aroma can be significantly affected by pouring in the sediment. A fresh, hoppy beer will usually have its fruity hop character increased by including the sediment in the pour. I've split many tall cans of IPA with friends and noticed that the second pour, which contains more sediment, has more hop intensity than the first. Potent flavor compounds stick to the yeast sediment of all beer, so most every style can have its character augmented by the presence of yeast.
Though many people still quantify beer clarity with quality, it seems many breweries are releasing unfiltered beer in many styles beyond just wheat ales. Most connoisseurs understand the benefits of not filtering beer, and have come to see hazy beer as beautiful. I see mass-produced, hazy IPAs on the horizon.